Mesogenic compounds, liquid-crystalline media and components for high-frequency technology

Abstract

A liquid-crystal medium which comprises a component A which consists of one or more compounds of the formula IA, in which the parameters have the respective meanings given in the claims or in the text, and to the corresponding, novel mesogenic compounds and to the preparation thereof. The use of these liquid-crystal media, in particular in components for high-frequency technology, and to components of this type which contain the media according to the invention, and to the production and use of these components. The components are suitable, in particular, for phase shifters in the microwave and millimeter wave region, for microwave and millimeter wave array antennae and very particularly for so-called tuneable “reflectarrays”.

The invention claimed is: 
     
       1. Liquid-crystal medium which comprises a component A which comprises one or more compounds selected from the compounds of the formulae IA-1 to IA-3 
       
         
           
           
               
               
           
         
       
       in which
 L 1  denotes halogen, 
 R 11  to R 13 , independently of one another, denote unfluorinated alkyl or unfluorinated alkoxy, each having 1 to 15 C atoms, unfluorinated alkenyl, unfluorinated alkenyloxy or unfluorinated alkoxyalkyl, each having 2 to 15 C atoms, or cycloalkyl, alkylcycloalkyl, cycloalkenyl, alkylcycloalkenyl, alkylcycloalkylalkyl or alkylcycloalkenylalkyl, each having up to 15 C atoms, provided that R 13  is not unfluorinated alkoxy, and which optionally comprises one or more compounds of the formula IB 
 
       
         
           
           
               
               
           
         
         in which 
       
       
         
           
           
               
               
           
         
          denotes one of the following groups: 
       
       
         
           
           
               
               
           
         
         
           
           
               
               
           
         
         R 11′  to R 14′ , independently of one another, denote unfluorinated alkyl or unfluorinated alkoxy, each having 1 to 15 C atoms, unfluorinated alkenyl, unfluorinated alkenyloxy or unfluorinated alkoxyalkyl, each having 2 to 15 C atoms, or cycloalkyl, alkylcycloalkyl, cycloalkenyl, alkylcycloalkenyl, alkylcycloalkylalkyl or alkylcycloalkenylalkyl, each having up to 15 C atoms, and alternatively one of R 13′  and R 14′  or both also denote H. 
       
     
     
       2. Liquid-crystal medium according to  claim 1 , wherein component A comprises one or more compounds of the formula IB which are selected from the group of the compounds of the formulae IB-1 and IB-3 to IB-4 
       
         
           
           
               
               
           
         
         wherein L 1  and X 1  are selected to provide a ring A 1  as defined in  claim 1  and in which the other parameters have the meanings given in  claim 1  under formula IB. 
       
     
     
       3. Liquid-crystal medium according to  claim 2 , wherein component A comprises one or more compounds of the formula IB-3 and/or of the formula IB-4, as indicated in  claim 2 . 
     
     
       4. Liquid-crystal medium according to  claim 2 , wherein component A comprises one or more compounds of the formula IB-1, as indicated in  claim 2 , in which X 1  denotes H. 
     
     
       5. Liquid-crystal medium according to  claim 2 , wherein component A comprises one or more compounds of the formula IB-1, as indicated in  claim 2 , in which X 1  denotes F. 
     
     
       6. Liquid-crystal medium according to  claim 1 , wherein, besides a component A, it additionally comprises one or more components selected from the group of the following components B to E:
 a strongly dielectrically positive component, component B, which has a dielectric anisotropy of 10 or more, 
 a strongly dielectrically negative component, component C, which has a dielectric anisotropy having a value of −5.0 or less, 
 a component, component D, which has a dielectric anisotropy in the range from more than −5.0 to less than 10.0 and consists of compounds having seven or more five- or six-membered rings, and 
 a component, component E, which likewise has a dielectric anisotropy in the range from more than −5.0 to less than 10.0 and consists of compounds having one to six five- or six-membered rings. 
 
     
     
       7. Liquid-crystal medium according to  claim 6 , which comprises a component B. 
     
     
       8. Liquid-crystal medium according to  claim 6 , which comprises a component C. 
     
     
       9. Liquid-crystal medium according to  claim 6 , which comprises a component D. 
     
     
       10. Liquid-crystal medium according to  claim 1 , which further comprises one or more compounds of the formula VI 
       
         
           
           
               
               
           
         
         in which 
         L 61  denotes R 61  and, in the case where Z 61  and/or Z 62  denote trans-CH═CH— or trans-CF═CF—, alternatively also denotes X 61 , 
         L 62  denotes R 62  and, in the case where Z 61  and/or Z 62  denote trans-CH═CH— or trans-CF═CF—, alternatively also denotes X 62 , 
         R 61  and R 62 , independently of one another, denote H, unfluorinated alkyl or unfluorinated alkoxy having 1 to 17 C atoms or unfluorinated alkenyl, unfluorinated alkenyloxy or unfluorinated alkoxyalkyl having 2 to 15 C atoms, 
         x 61  and X 62 , independently of one another, denote F or Cl, —CN, —NCS, —SF 5 , fluorinated alkyl or alkoxy having 1 to 7 C atoms or fluorinated alkenyl, alkenyloxy or alkoxyalkyl having 2 to 7 C atoms, or —NCS, 
         one of Z 61  and Z 62  denotes trans-CH═CH—, trans-CF═CF— or —C≡C— and the other, independently thereof, denotes trans-CH═CH—, trans-CF═CF— or a single bond, and 
       
       
         
           
           
               
               
           
         
         
           independently of one another, denote 
         
       
       
         
           
           
               
               
           
         
       
     
     
       11. Liquid-crystal medium according to  claim 1 , which comprises a compound of the formula IB. 
     
     
       12. Process for the preparation of a liquid-crystal medium according to  claim 1 , comprising mixing one or more compounds of the formula IA, as indicated in  claim 1 , with one or more further compounds and/or with one or more additives. 
     
     
       13. Component for high-frequency technology, which contains a liquid-crystal medium according to  claim 1 . 
     
     
       14. Microwave antenna array, which comprises one or more components according to  claim 13 . 
     
     
       15. Process for tuning a microwave antenna array, comprising electrically addressing a component according to  claim 13 . 
     
     
       16. Compound of one of the formulae IA-1 to IA-3: 
       
         
           
           
               
               
           
         
       
       in which
 L 1  denotes halogen, 
 R 11  to R 13 , independently of one another, denote unfluorinated alkyl or unfluorinated alkoxy, each having 1 to 15 C atoms, unfluorinated alkenyl, unfluorinated alkenyloxy or unfluorinated alkoxyalkyl, each having 2 to 15 C atoms, or cycloalkyl, alkylcycloalkyl, cycloalkenyl, alkylcycloalkenyl, alkylcycloalkylalkyl or alkylcycloalkenylalkyl, each having up to 15 C atoms, provided that R 13  is not unfluorinated alkoxy.